The present invention relates in general to fabrication methodologies and resulting structures for semiconductor devices. More specifically, the present invention relates to a multi-layer spacer structure for forming air-gap spacers with an etch-stop layer in fin-type field effect transistors (FinFETs).
A FinFET is a FET structure that has a conducting channel wrapped by a thin piece of silicon “fin”. The thickness of the fin determines an effective channel length of the device. A FinFET can include air-gap spacers, which can provide enhanced electrical performance by reducing parasitic capacitance between a gate and source/drain regions of the FinFET.